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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The treatment of platinum refinery wastewater using an evaporative crystallizer

Luvuno, Jabulani Heavenson 03 1900 (has links)
South Africa is a water scarce country. The expansion of the industrial, mining, and agricultural sectors to meet the needs of South Africa’s growing population requires more water. There is therefore an urgent need to develop effective wastewater treatment processes in order to recover and reuse water. This dissertation presents the treatment of an acidic wastewater stream from a platinum refinery which at present is being disposed of by contract with a waste disposal company. The major concern in treating the acid effluent stream is the high concentration of sodium ions (18 200 mg/l) and chloride ions (104 900 mg/l). The precipitation process is used to treat wastewater, but ultimately it generates more secondary waste as a sludge. The other process that is used to treat wastewater is reverse osmosis (RO). RO is usually preferred in the last stage of the treatment because the process is more expensive as membranes need to be replaced regularly. The approach used in this research focuses on evaporating liquid, consequently concentrating the remaining solution until the ions in the solution crystallize. The liquid produced is recycled back into the platinum plant for reuse, and the remaining salt crystals are collected as the useful product. The proposed water treatment process produces dilute hydrochloric acid as the condensate and a crystallized sodium chloride rich residue. The refinery is currently disposing of around 20 000 l/day of wastewater to landfills. The proposed treatment process can recover half of the volume of the wastewater stream to the refinery, helping reduce the fresh water consumption of the process by 10 000 l/day. Furthermore, this will reduce the volume of wastewater going to disposal by a half, namely only 10 000 l/day will need to be disposed of. The amount of Cl that can be recovered is variable and depends on the quantity of chloride in the wastewater. In the two samples processed the recovery was between a 2,5 w% and 10,7 wt% aqueous HCl solution. This corresponds to a saving of between 250 to 1000 kg/day of HCl. As the concentration of the recovered solution is variable, the recycling process would need to monitor the composition of the recycled stream and make up the acid concentration to some fixed value for reuse in the prices. The production of a dilute hydrochloric acid stream should be particularly attractive to the platinum refinery as the operation of the refinery requires hydrochloric acid as a feed. Thus, by recycling the wastewater, the refinery would reduce the volume of wastewater to be disposed of thereby reducing the cost of disposal of the waste while simultaneously reducing the cost of buying fresh hydrochloric acid. The proposed recovery of liquid and recycling it back to the refinery, will also reduce the environmental impact of the refinery, and very importantly in a water scarce country, reduce the freshwater consumption of the process. / Physics / M. Sc. (Physics)
22

An evaluation of solid waste management practice at Carnival City, Brakpan

Pholose, Annah Motshwane 03 1900 (has links)
Waste management is a global concern and landfill sites are facing a crisis of handling capacity. This is worsened by the fact that many consider landfilling as an environmentally responsible and cost-effective solution to waste disposal. Carnival City generates vast quantities of solid waste on a daily basis and most of it ends at the landfill, which it acknowledges that it’s a wastage of recoverable resources, hence its commitment of “zero-waste-to-landfills by 2022”. This study evaluated solid waste management practices at Carnival City Casino in Brakpan. Informed by an interpretive paradigm, qualitative methods including interviews, observations, photographs and document reviews were used to collect data. Based on abductive reasoning, the waste management hierarchy and the ISO 14001 standard were used as frameworks for recontextualising and presenting the collected data. The waste hierarchy sets out the preferred order of waste management practices, from the most favoured to the least preferred option. The effectiveness of current waste management practices is limited as Carnival City heavily depends on landfilling and implement waste minimisation, reuse, recycling and recovery on a small scale. Absence of a waste separation at source policy limits recycling activities significantly. The researcher noted the presence of some areas of conformity to South African legislation pertaining to waste management, international standards and Carnival City’s standard operating procedures, and some areas of good practice. The study showed that there is room for improving concerning Carnival City’s current waste management practices. It recommends that waste management training and awareness be undertaken on a continuous basis to improve current practices and ensure that more waste is diverted from landfill sites. Investment into waste to energy technologies should be considered to help Carnival City to meet Sun International’s commitment of “zero-waste-to-landfills by 2022”. Recycling must be maximised and its environmental and financial benefits be highlighted. The research recommends developing of a separation at source policy and its enforcement by the Environmental Committee as the absence of the documented procedures results in deviations from environmental objectives. Offenders who do not follow procedures should be duly punished. It also recommends that a disciplinary action and a fine be introduced for kitchens that will deviate from the policy. / Environmental Sciences / M. Sc. (Environmental Management)
23

Waste tyre management problems in South Africa and the possible opportunities that can be created through the recycling thereof

Mahlangu, Mpanyana Lucas 04 1900 (has links)
The research work critically analyzed the factors responsible for imprudent waste tyre management in South Africa. As an approach to determine the complexity of the problem, questionnaires were sent to one hundred and sixty (160) respondents in conjunction with interviews. Perusal of literature and interaction with industry involved in waste tyre processing to further gain knowledge of the problem and possible solutions that can be solicited to address the problem. Findings revealed that, lack of clear, focused legislation that guide the handling, disposal and processing of waste tyres remain the challenge. It is also deduced that recycling of waste tyres can provide economic benefits and opportunities. It is recommended that South Africa develop appropriate legislation that deals with handling, treatment and disposal of waste tyres, develop an incentive programme to set up initiatives as well as developing skilled and capacitated enforcement agency. / Environmental Sciences / M.A. (Environmental Management)
24

Household participation in domestic waste disposal and recycling in the Tshwane Metropolitan Area : an environmental education perspective

Kamara, Agnes Jonton 02 1900 (has links)
The aim of this study was to investigate the factors influencing household awareness and participation in domestic waste disposal and recycling, focusing on environmental educational (EE), wealth and location of suburb. The study was carried out in four suburbs in the Tshwane Metropolitan Area (TMA), namely Waterkloof, Lynnwood, Sunnyside and Mamelodi. A literature review was conducted, covering concepts of domestic waste management - waste prevention, collection, recycling and reuse, followed by household analysis using empirical data. The analysis shows that there is a low level of household awareness about the environmental implications of domestic waste management in TMA, and hence low level of participation in domestic waste sorting, disposal and recycling. Among relevant factors are the level of EE and income of the households across all suburbs. This calls attention to the need for strengthening EE not only in schools, but also in suburbs using both formal and informal outreach programmes. / Educational Studies / M. Ed. (Environmental Education)
25

A review of solid waste management practices in Polokwane City

Maluleke, Prudence Hlamarisa 08 May 2014 (has links)
Bibliographical refernces appear at the end of each chapter / This study reviews solid waste management practices in Polokwane City. The study area covered some of the residential areas in Polokwane City; namely; Ivy Park, Fauna Park, Welgelegen, Westernburg and the City Centre. This article describes two main methods that were used to collect data; that is Qualitative and Quantitative method. Field survey was also made to validate data obtained from the participants that were interviewed during qualitative data process. After framing the problem, the objectives of Solid Waste Management Practices in Polokwane City were briefly outlined as follows: • Assess solid waste management practices in Polokwane City. • Make comparison on how households and the municipality take responsibility in storing, collecting, transporting, treating and disposing solid waste. • Investigate what problems the City encounters in managing solid waste. • Make relevant recommendations aimed at improving solid waste management practices within the City. The service management was administered by the municipality and private sector. From the five study residential areas, the Municipality manages waste in the City Centre while the private sector manages waste in the other residential areas. However, the City continues to play an administrative role over the contracted service provider. Statistical results were presented in figures and tables. The results showed the storage habits, frequency of collection, mode of transport and methods of disposal for solid waste in Polokwane City. The only method of disposal in the city was found to be landfilling. Activities that took place at the landfill site, such as reclaiming were outlined together with the economic values that these activities add to the City. The study also revealed that as population increases, the amount of solid waste generated also increased. / Environmental Sciences / M. Sc. (Environmental Management)
26

Assessment of respiratory risks associated with exposure to particulate matter (PM2.5) in informal waste pickers in a landfill site in KwaZulu-Natal

Dalasile, Monica Ntombohlanga January 2015 (has links)
Submitted in fulfillment of the requirements for the Degree of Master of Technology Degree : Environmental Health, Durban University of Technology, Durban, South Africa, 2015. / Introduction Informal waste picking has both economic and environmental benefits, however there are many health risks associated with this activity. This cross sectional descriptive study assessed the respiratory health risks and dust (PM2.5) exposure among informal waste pickers operating at the New England landfill site in the Msunduzi Municipality. Data was collected from 102 informal waste pickers using a validated questionnaire adapted from the British Medical Research Council and American Thoracic Society. Our study population comprised of 66.4°/o women with a mean age of 36.7 years. Women reported greater use of safety shoes and gloves compared to men. Very few participants used dust masks or respirators. Results showed a high prevalence of chronic cough (57o/o), wheeze (51°/o) shortness of breath (31.6°/o) and cough with phlegm (29.0°/o) among all participants. Among those who reported having ever smoked, there was a significantly higher prevalence of cough with phlegm (45.2°/o p=0.02) and wheeze (73.1°/o, p= 0.05). Similarly, there was a bivariate association between current smoking and wheeze (p=0.02) and between ever smoked and wheeze {p< 0.05). A random sample of 28 waste pickers was chosen from the 102 participants for personal sampling. The levels and distribution of time weighted average to PM2.5 were calculated during an 8 hour working period. Average personal sampling levels of PM2.5 were very high compared to environmental levels. Personal sampling results showed a maximum exposure of 431 J.,Jg/m 3 and a mean of 187.4 J.,Jg/m 3 compared to a maximum level of 27.9 J.,Jg/m 3 and a mean of 16.5 J.,Jg/m 3 for environmental sampling. Mean personal sampling results significantly exceeded recommended eight hour time weighted average for South African National Standard for Occupational Exposure Limit (Republic of South Africa OHS ACT 85 of 1993), World Health Organisation and United State Environmental Protection Agency guidelines for PM2.5, while the environmental mean was within guidelines. This study showed that waste pickers are exposed to high levels of PM2.5 while working at the landfill site. Limited or no use of personal protective equipment increases risk of dust exposure and adverse respiratory effects. The relatively high prevalence of cough, shortness of breath and wheeze symptoms among these informal waste pickers may be linked to exposure to dust at the landfill site / PDF copy unavailable. please refer to hard copy for full text information / M
27

Action competence and waste management: a case study of learner agency in two Grahamstown eco-schools / Probing the development of action competence amongst learners participating in school waste management activities : a case of two Grahamstown schools

Chiphwanya, Nellie Chimwemwe January 2011 (has links)
There has been a growing need in environmental education to develop students' ability and will to take part in democratic processes that enable them take environmental action in their local environment. This study examined learner action competence in waste management practices in two primary school contexts in the Eastern Cape, South Africa. An interpretive case study design is used to probe how learner participation in Eco-School waste management practices enabled the acquisition of knowledge in purposeful learning and action experiences that developed the vision and agency of informed action. The research was centred on two guiding questions: 1. How informed, purposeful and action-orientated is learner participation in Eco-School waste management activities? 2. What Eco-School waste management activities are fostering active participation towards a learner-led agency? Educators in the two schools were interviewed and Eco-School portfolios were examined for evidence of the learning activities and learner achievement. This provided the contextual data for reviewing focus group interviews to probe what was significant to learners, what they came to know and how they had contributed to the process of developing better waste management in the Eco-School context. The evidence generated in the study was used to identify the roles of the various players, the significant activities and processes that enabled and constrained the emergence of learner-led agency. The main findings in the study were that teacher intentionality and school management ethos were significant in engaging learners in meaningful waste management activities in both cases. The study also revealed that although most of the waste management activities in both cases were teacher-initiated, there were spaces open for learner initiatives. However, it appeared that the activity based waste management practices mostly allowed learners to learn how to do waste management more than allowing them to find out more about the scope and nature of ii the problem of waste. This then resulted in learners talking more about what they were doing with waste than talking about what they knew about waste. There were differences in the way in which learners approached waste in the two cases. In the one case, Kingswood Junior School learners used waste artistically and carried out activities that allowed for better use of waste resources like paper while in the other School, Grahamstown SDA School, learners approached waste as a resource for making money. However, in both cases, learners appeared to enjoy the positive experiences of doing things that contributed to a cleaner environment and were of benefit to others and this gave them a sense of pride to share their experiences with others. This study was significant as it allowed me to probe learner participation and examine the development of their action competence through listening to the voices of the learners themselves and understanding what was important to them about the knowledge they gained and their vision of better waste management.
28

Waste tyre management problems in South Africa and the possible opportunities that can be created through the recycling thereof

Mahlangu, Mpanyana Lucas 04 1900 (has links)
The research work critically analyzed the factors responsible for imprudent waste tyre management in South Africa. As an approach to determine the complexity of the problem, questionnaires were sent to one hundred and sixty (160) respondents in conjunction with interviews. Perusal of literature and interaction with industry involved in waste tyre processing to further gain knowledge of the problem and possible solutions that can be solicited to address the problem. Findings revealed that, lack of clear, focused legislation that guide the handling, disposal and processing of waste tyres remain the challenge. It is also deduced that recycling of waste tyres can provide economic benefits and opportunities. It is recommended that South Africa develop appropriate legislation that deals with handling, treatment and disposal of waste tyres, develop an incentive programme to set up initiatives as well as developing skilled and capacitated enforcement agency. / Environmental Sciences / M.A. (Environmental Management)
29

Household participation in domestic waste disposal and recycling in the Tshwane Metropolitan Area : an environmental education perspective

Kamara, Agnes Jonton 02 1900 (has links)
The aim of this study was to investigate the factors influencing household awareness and participation in domestic waste disposal and recycling, focusing on environmental educational (EE), wealth and location of suburb. The study was carried out in four suburbs in the Tshwane Metropolitan Area (TMA), namely Waterkloof, Lynnwood, Sunnyside and Mamelodi. A literature review was conducted, covering concepts of domestic waste management - waste prevention, collection, recycling and reuse, followed by household analysis using empirical data. The analysis shows that there is a low level of household awareness about the environmental implications of domestic waste management in TMA, and hence low level of participation in domestic waste sorting, disposal and recycling. Among relevant factors are the level of EE and income of the households across all suburbs. This calls attention to the need for strengthening EE not only in schools, but also in suburbs using both formal and informal outreach programmes. / Educational Studies / M. Ed. (Environmental Education)
30

A review of solid waste management practices in Polokwane City

Maluleke, Prudence Hlamarisa 08 May 2014 (has links)
Bibliographical refernces appear at the end of each chapter / This study reviews solid waste management practices in Polokwane City. The study area covered some of the residential areas in Polokwane City; namely; Ivy Park, Fauna Park, Welgelegen, Westernburg and the City Centre. This article describes two main methods that were used to collect data; that is Qualitative and Quantitative method. Field survey was also made to validate data obtained from the participants that were interviewed during qualitative data process. After framing the problem, the objectives of Solid Waste Management Practices in Polokwane City were briefly outlined as follows: • Assess solid waste management practices in Polokwane City. • Make comparison on how households and the municipality take responsibility in storing, collecting, transporting, treating and disposing solid waste. • Investigate what problems the City encounters in managing solid waste. • Make relevant recommendations aimed at improving solid waste management practices within the City. The service management was administered by the municipality and private sector. From the five study residential areas, the Municipality manages waste in the City Centre while the private sector manages waste in the other residential areas. However, the City continues to play an administrative role over the contracted service provider. Statistical results were presented in figures and tables. The results showed the storage habits, frequency of collection, mode of transport and methods of disposal for solid waste in Polokwane City. The only method of disposal in the city was found to be landfilling. Activities that took place at the landfill site, such as reclaiming were outlined together with the economic values that these activities add to the City. The study also revealed that as population increases, the amount of solid waste generated also increased. / Environmental Sciences / M. Sc. (Environmental Management)

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